At a printing site where printing is performed by POD (Print On Demand), a plurality of each of an image forming device for forming an image on a sheet, an image input device for inputting image data, and a sheet processing device for processing the printed sheets are interconnected via a network. The sheet processing devices are known as a binding device for binding a plurality of sheets, a stapling device for stapling a plurality of sheets and a case making device for covering a bundle of the bound sheets. In the printing site where printing is performed by POD, print processing using a network system, which is based upon a print job generated by a client computer and a print job introduced via the Internet, is executed. At such a printing site, one or a plurality of operators are employed in order to manage the plurality of printing devices. Furthermore, a process control server for managing each device, the contents of operations performed by the operators and the processing in a unified manner is connected to the network.
While cooperating with a front-end server, the process control server considers which job should be assigned to which device and decides to which job or device an operator should be deployed in accordance with receipt or input of a print job. When such a decision is made, the process control server checks the status and capability of each device and the state of the connection of the finisher and executes the scheduling of the overall system while estimating the processing time for each job.
Among the devices, there are devices connected via the network and on-line finishing devices that are not on the network. It is required that each of these devices be equipped with means capable of receiving instructions from the process control server. The job assigned to each device is processed in the length of time thus scheduled by the process control server. In the event that an unforeseen error or the like occurs, a message is displayed on a display unit that belongs to, e.g., the image forming device. The message relates to a maintenance operation for allowing the image forming device itself to recover from the error (see the specification of Japanese Patent Application Laid-Open No. 6-68104).
In the example of the prior art cited above, however, when the process control server acquires information from each device, the server merely acquires only predetermined information in one-sided fashion. This information is not satisfactory as information for resetting the process. A problem which arises, therefore, is that accurate process reset cannot be performed solely with the information acquired.
Further, in the event that an error of some kind has occurred in the image forming device, display of a specific error message can be presented to the operator using the display unit of the device. In the present state of the art, however, the error message is one that has been decided uniquely and is not a message that takes the overall process of the network system into account. For example, if paper has become jammed in a certain image forming device, the particular reason for jamming cannot be ascertained. Accordingly, the process control server cannot decide whether this image forming device should be as a device to be assigned a job or whether it should be temporarily excluded from a device to which a job is assigned.
Meanwhile, if paper jamming has occurred, the image forming device merely displays a message such as “CLEAR PAPER JAM” on the display unit of this device per se; no consideration is given to a so-called intelligent display scheme. Consider as an example a case where a network includes an image forming device that jams frequently. It is necessary to accurately determine not only the number of times jamming has occurred on a particular day but also the cause of the paper jam and the status of the image forming device, and to render a final decision on operation. For example, if the cause of jamming is the moisture of the paper fed, it is not necessary to call a serviceman but it is necessary to be mindful of control of the device environment, especially humidity. Changing the setting of an air conditioner, for example, is conceivable as an operation that can be performed by the operator in such case. However, present-day process control servers cannot make such flexible decisions and responses as the circumstances demand.
Further, consider a situation where a certain image forming device has run out of size A4 paper. In such case it is impossible for a process control server to decide whether to instruct an operator to supply size A4 paper to this image forming device, whether this print job should be handed over to another image forming device in which size A4 paper has been loaded or, if size A3 paper has been loaded in the image forming device that has no A4 paper, whether 2-up printing should be performed on the size A3 paper by this image forming device and whether the size A3 paper thus printed on should be cut by the operator using a trimmer to obtain a printing effect equivalent to that which would have been obtained by printing on size A4 paper.
Further, even if the operator is instructed to supply the paper, at present only a predetermined message such as “SUPPLY SIZE A4 PAPER” is displayed. Furthermore, even if the process control server issues an order to perform an operation, the server cannot send this order to the operator upon ascertaining whether the operator is accustomed to this work or what the state of health of the operator is on that particular day. By way of example, suppose that the operator has an aggravated back condition on a particular day and, as a consequence, a considerable length of time would be required for the operator to carry the paper from a warehouse where it has been stocked and load the paper into the image forming device in order to supply it with the size A4 paper. Such a determination cannot be made and the situation cannot be dealt with using a mechanical control method of a process control server.
When a problem of the above-mentioned kind arises, it is vital that a decision be made by the on-site operator. However, at a printing site of such scale that a large number of devices are connected in the system, it is difficult for the operator to grasp the overall system and it is highly likely that the decision will be made in accordance with an empirical rule. It is difficult to maintain that such an independent decision rendered by an operator will have an advantageous effect upon the process as a whole. For example, in a case where an image forming device has run out of size A4 paper, as mentioned above, assume that the operator has made an independent decision to print on size A3 paper in the 2-up format and to cut the paper after printing. Nevertheless, one on-site operator cannot ascertain all the necessary information, such as whether a trimmer has been installed at the printing site, whether the trimmer is in a state where it can be reserved for use, whether a worker skilled at handling the trimmer is available, and whether the work schedule of the trimmer operator will allow him to do the job.